check engine code?

i have a 2004 dodge stratus and my check engine lights on and i had it put on machine and the code came up P0507 and the parts store said i need it serviced but service said its a non repairable part so it just needs replacing ..in which im positive i can do myself but nobody seems to be able to tell me what part i need and if the parts store is right that it might need adjusting ..the dealer just keeps telling me they need it put on their machine to check code ..which i feel is a waste of money and time if ive already had it done..can someone tell me what the code

P0507 is please

P0507-IDLE SPEED HIGH PERFORMANCE


---------check this forum too.

http://www.dodgeforum.com/forumid_43/tt.htm